Mobile Communication System, Location Manager and Routing Manager

1. A cellular communication system wherein a mobile communication service area is divided into a plurality of location registration areas, the cellular communication system comprising: a mobile router and at least one mobile node, moving in a moving body and in a master-slave relationship, the mobile router performing location update of the mobile node that does not perform the location update, if the mobile node is an a dormant state; a unit for retaining a flag indicating whether the mobile router is in an active state or a dormant state; a unit for inquiring about routing address information of the mobile router in an active state based on a value of the retained flag when paging is performed to at least one of the mobile nodes; and a unit for performing paging to the at least one mobile node, using the obtained routing address information of the mobile router in an active state as a result of the inquiry.

2. The cellular communication system according to claim 1 , further comprising a unit for setting the flag to a first value indicating an active state in response to a first signal sent from the mobile node and indicating start of communication, and setting the flag to a second value indicating a dormant state in response to a second signal sent from the mobile node and indicating end of communication.

3. A cellular communication system wherein a mobile communication service area is divided into a plurality of location registration areas, the cellular communication system comprising: a mobile router and at least one mobile node, moving in a moving body and in a master-slave relationship, the mobile router performing location update of the mobile node that does not perform the location update, if the mobile node is in a dormant state; a routing manager; and a location manager, the routing manager comprising: a table for storing routing address information for the mobile router; and a unit for, when the routing address information for the mobile router in the table is updated, notifying the updated routing address information to the location manager; and the location manager comprising: a table for storing the routing address information notified by the routing manager as location area information of the mobile router in an active state; and a unit for performing paging to at least one of the mobile nodes using the location area information of the mobile router in an active state stored in the table.

4. A location manager for use in a cellular communication system wherein a mobile communication service area is divided into a plurality of location registration areas, and a mobile router in a dormant state moving with a plurality of mobile nodes in a dormant state, the mobile router performing location update of the mobile nodes on behalf of the mobile nodes that do not perform the location update, the location manager comprising: a unit for retaining a flag indicating whether the mobile router is in an active state or a dormant state; a unit for inquiring about routing address information of the mobile router based on a value of the retained flag when paging is performed to at least one of the mobile nodes; and a unit for performing paging to at least one of the mobile nodes in a master-slave relationship with the mobile router, using the routing address information of the mobile router in an active state obtained as a result of the inquiry.

5. The location manager according to claim 4 further comprising a unit for setting the flag to a first value indicating an active state in response to a first signal sent from the mobile node and indicating a start of communication, and setting the flag to a second value indicating a dormant state in response to a second signal sent from the mobile node and indicating an end of communication.

6. A location manager for use in a cellular communication system wherein a mobile communication service area is divided into a plurality of location registration areas, and a mobile router in a dormant state moving with a plurality of mobile nodes in a dormant state, the mobile router performing location update of the mobile nodes on behalf of the mobile nodes that do not perform the location update, the location manager comprising: a table for storing routing address information for the mobile router, which is notified from a routing manager whenever the routing address information is updated, as location area information for the mobile router; and a unit for performing paging to at least one of the mobile nodes in a master-slave relationship with the mobile router, using the location area information of the mobile router in an active state stored in the table.

7. A routing manager used for a cellular communication system wherein a mobile communication service area is divided into a plurality of location registration areas, and a mobile router in a dormant state moving with a plurality of mobile nodes in a dormant state, the mobile router performing location update of the mobile nodes in a master-slave relationship with the mobile router, on behalf of the mobile nodes that do not perform the location update, the routing manager comprising: a table for storing routing address information of the mobile router in an active state; and a unit for replying the routing address intonation stored in the table in response to an inquiry from a location manager about the routing address information for the mobile router in an active state.

8. A routing manager used for a cellular communication system wherein a mobile communication service area is divided into a plurality of location registration areas, and a mobile router in a dormant state moving with a plurality of mobile nodes in a dormant state, the mobile router performing location update of the mobile nodes in a master-slave relationship with the mobile router, on behalf of the mobile nodes that do not perform the location update, the routing manager comprising: a table for storing routing address information for the mobile router in an active state; and a unit for, when the routing address information for the mobile router in an active state in the table is updated, notifying the updated routing address information to a location manager.